Method of making an article for use in sound recording and reproducing instruments

ABSTRACT

A method for making an article of manufacture for use in sound recording and/or reproducing apparatus by forming a single piece in an injection molding step. The single piece has a chassis portion, a lever portion, and a number of other portions connecting the chassis portion to the lever portion. The chassis portion is then connected to the lever portion by a separate connecting member and a predetermined number of the connecting portions are severed. If all of the connecting portions are not severed, only one disposed in the direct vicinity of the separate connecting member is left unsevered.

United States Patent Westphal METHOD OF MAKING AN ARTICLE FOR USE IN SOUND RECORDING AND 'REPRODUCING INSTRUMENTS 72] Inventor: Klaus Westphal, Berlin, Germany [73] Assignee: Telefunken Patentyerwerlungsesellschatt -m.b.l l., Ulm/Danube, Germany [30] Foreign Application Priority Data May 10, 1967 Gennany 33829 [52] US. Cl ..29/527.1, 264/138, 274/1 R [51] Int. Cl. ..B23p 25/00 [58] Field of Search ..29/527.1, 169.5; 264/138, 154, 264/161, 242, 261, 277; 220/315 [56] References Cited UNITED STATES PATENTS 2,896,840 7/ 1959 Hendry ..264/ 154 X 1451 Aug. 15, 1972 3,263,009 7/1966 Vidal ..264/154 x 3,394,212 7/1968 Maloney ..264/1S4 3,592,354 7/1971 Nielsen ..220/315 FOREIGN PATENTS on APPLICATIONS 283,738 1/1923 Great Britain ..264/242 718,339 9/1965 Canada ..264/242 2,646 12/1903 Great Britain ..220/315 1,236,770 3/1967 Germany ..264/242 Primary Examiner-J. Spencer Overholser Assistant Examiner-John E. Roethel Attorney-Spencer & Kaye [57] ABSTRACT A method for making an article of manufacture for use in sound recording and/or reproducing apparatus by forming a single piece in an injection molding step. The single piece has a chassis portion, a lever portion, anda number of other portions connecting the chassis portion to the lever portion. The chassis portion is then connected to the lever portion by a separate connecting member and a predetermined number of the connecting portions are severed. If all of the connecting portions are not severed, only one disposed in the direct vicinity of the separate connecting member is left unsevered.

4 Claims, 6 Drawing Figures PATENTEDAUB 1 I912 3.683.489

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SHEET 2 UF 3 mvzuroa Klqus Westphcl BY w 5 214 ATTORNEYS PATENTEDAUB I912 3.683.489 sum 3 or 5 INVENTOR Klaus Westphol BY W f ATTO RNEYS METHOD OF MAKING AN ARTICLE FOR USE IN SOUND RECORDING AND REPRODUCING INSTRUMENTS CROSS REFERENCE TO RELATED APPLICATION This application is a division of copending application, Ser. No. 701,948, filed Jan. 31, 1968, now abandoned, entitled ARTICLE FOR USE IN SOUND RECORDING AND REPRODUCING INSTRU- MENTS.

BACKGROUND OF THE INVENTION The present invention relates to a method for making an article of manufacture for use in sound-recording and/or reproducing instruments formed of a thermoplastic synthetic material in a single piece by injection-molding and, more particularly, to a base plate having a chassis and lever portions; each lever portion being connected to the chassis portion by means around which the lever portion may be pivoted with respect to the chassis portion.

In magnetic sound instruments for the home, a substantial part of the manufacturing cost stems from the mechanical assembly of the instrument. Even with instruments in the less expensive price ranges, thereare limits to how far costs can be reduced, since certain minimal requirements or standards must be met to assure quality in reproduction. These standards, in order to be maintained, require precise workmanship in assembling the operating components of the instrument.

In keeping with the standards required, one approach known to the industry for reducing the cost of installation and, therefore, the price at which the instrument is sold has been to produce a base plate for supporting the various operating components of the instrument, by a die-casting or injection-molding process. The various mountings and bearing points for the operating instrument components are produced in such a process as part of the unitary whole comprising the base plate. Even though a base plate produced in such a manner eliminates many of the time-consuming and, therefore, costly steps required in the installation process including simplifying or eliminating the separate step of preparing bearing surfaces, it still continues to be necessary to separately install a multitude of separately manufactured components, as for example, brakes, forward and reverse levers, angular guide members, voltage selector plates, soldering ledges etc.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to overcome the above-discussed drawbacks.

The present invention has as a further object to substantially reduce the manufacturing costs of soundrecording and/or playback instruments.

Yetanother object of this invention is to provide a relatively simple method for making a one-piece injection-molded article of manufacture for sound-recording and/or playback instruments.

In brief, the present invention deals with the problems discussed above by providing a one-piece injection-molded base plate having joined to it both chassis and lever portions, by means of connecting portions, to form an integral whole. The article, according to the invention, further provides that the lever portions will be movable with respect to the chassis portion by severing, or eliminating in the case of each lever portion so provided, all of the connecting portions except one; said one remaining connecting portion providing for each lever portion a fulcrum around which each lever can be moved.

In yet another form of the invention all of the connecting portions joining each lever portion provided to the chassis portion are severed and a separate connecting member is provided to join each lever portion to the chassis portion. The separate connecting member, is adapted to serve as a fulcrum about which the lever portion can be moved with respect to the chassis portion of the base plate.

A base plate, thus formed, will result in relatively low manufacturing costs, in-as-much as, all of the components which have no direct bearing on the quality of recording and reproduction of the instrument, (e.g. levers, bearings and pivotal means) which previously had to be separately manufactured and installed, can now be injection-molded in one operating step. Thus additional expenditures for separately producing these components and for separately installing them in the instrument, which step required both mounting and fastening, are eliminated and, as a consequence, the overall manufacturing cost of the instrument is reduced.

In order to guarantee good molding of the lever portions during the injection-molding process, a number of contact points or connecting portions are provided between the lever and chassis portions of the article. Preferably, for each lever portion provided, one of these connecting portions is so disposed and is molded in such a configuration that it will serve as a fulcrum for the lever after all the other connecting portions have been separated. This reduced cross section connecting portion will include a pivot axis about which the lever can be pivotally moved with respect to the chassis port1on.

In another form of the invention, a separate connecting member made from thermoplastic synthetic material and having a reduced cross section in the region of its center is used. In this embodiment of the invention the chassis and each lever portion are provided with attaching means whereby the separate connecting member can be attached to each portion, respectively, hence, connecting one to the other. The preferred form of the attaching means in each portion, respectively, is as a recess. The separate connecting member is suitably configured to complement these recesses so that it can be attached or inserted into them with ease. After inserting the separate connecting member into the provided recesses all other connecting portions are severed, and the separate connecting member will serve as a fulcrum about which'the lever portion can pivotally be moved with respect to the chassis portion. One advantage of this form of the invention is that all but the separate connecting member may be manufactured from a less expensive material. This, of course, would not be possible in the previously discussed form of the invention.

By a further aspect of the invention means is provided whereby the fulcrum or connecting means is reinforced by relieving some of the stresses encountered under heavy load conditions. Such a means includes two holes that extend through the connecting means, whether it be the unsevered connecting portion or the separate connecting member. These holes extend in parallel relationship both to each other and to the pivot axis in the connecting means. One hole is positioned in the connecting means on the lever side of the pivot axis; the other is positioned in the connecting means on the chassis side. A U-shaped member, each leg of which is insertable through the holes thus defined in the connecting means is also provided, such that, when the U-shaped member is so inserted into the holes the connecting means will be reinforced.

BRIEF DESCRIPTION OF THE DRAWINGS The invention both as to structure and further ob jects and advantages thereof may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a plan view of the invention as assembled in a recording and/or reproducing instrument.

FIG. 2 is a section of FIG. I viewed along line 2-2.

FIG. 3 is an enlarged view of a portion of FIG. 1.

FIG. 4 is a section of FIG. 3 viewed along line 4-4.

FIG. 5 shows another embodiment according to the invention.

FIG. 6 is an enlarged view of FIG. 5 viewed along line 6-6 just prior to insertion of a connecting means.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, the base plate 1 consists of a single piece of thermoplastic synthetic material which was injection-molded to include first and second parts formed as a chassis portion 2, and lever portions 3, respectively. Also included as part of the single piece are bearings 4 required for the operating functions. For enhancing its stability, the chassis 2 has been inserted into a frame 5 which preferably simultaneously forms the instrument housing. The levers 3 may be either control levers or forward and reverse levers. Some of the bearing blocks 4 include cylindrical bores 6 for the insertion of connecting bolts or spindles (not shown) for rotatably mounted components. The brakes 7 are connected to the chassis in the same manner as the levers 3.

Referring now to FIG. 3, the same shows an enlarged portion of FIG. 1. In particular, an enlarged view of a lever 3 is depicted and is shown to be located within a cut-out 2' in the chassis portion 2 and directly connected to the chassis 2 via a connecting portion 8 which serves as a fulcrum and includes a pivot axis in a region 9 of reduced cross section. Openings 10 and 10, for the insertion of push or pull rods (not shown), which would be connected to, for example, an advance lever 3, are simultaneously formed in the same injectionmolding process which produces the article 1 together with its various portions. Extending through the fulcrum or connecting portion 8 are holes 11, in parallel relationship to each other and to the pivot axis in the connecting portion 8. One hole 11 is located on the lever 3 side of reduced cross section region 9 and the other hole 11 is located on the chassis 2 side of region 9.

As best seen in FIG. 4, a U-shaped element 12 is insertable, one leg in each of said holes 11, thereby to reinforce the pivot axis of the region 9 by relieving stresses resulting under heavy load conditions. Referring again to FIG. 3, when the article 1 is produced, the lever 3 is initially connected to the chassis at three places 8, 13 and 14 in order to guarantee a better molding of the individual parts. The connecting portions 13 and 14 are shown in FIG. 3 in phantom to indicate their location before being severed. One of these connecting portions 8 has a cross section which is reduced in such a manner that it serves as the fulcrum for the lever 3 after the other connecting portions 13 and 14 have been severed in any well known manner, for example, by stamping.

In the embodiment according to FIGS. 5 and 6, a separately produced connecting member 15 is being used which consists of a thermoplastic synthetic material and which has a reduced cross section 19in its center region. This connecting member 15 fits exactly into the recesses 16 and 17, respectively, provided therefor in a mounting block 20' molded integrally with the chassis portion 2, on one hand, and in the lever portion 18, on the other hand. After insertion of the connecting member 15, the connecting portion at 21 which connects the lever 18 with the chassis 2 during the injection-molding process is severed in any well known manner. The connecting member 15 now serves as the fulcrum for the lever 18 in exactly the same manner as the connecting portion 8 of FIGS. 1-4. Here, as in the previously discussed embodiment, two holes 22 extend through the connecting member 15, one on each side of the pivot axis provided by cross section 19. The holes 22 extend in parallel relationship both with respect to each other and to the pivot axis. A U-shaped element can be inserted into holes 22 thereby to relieve the fulcrum or connecting member 15, particularly when heavy loads are met.

The embodiment of the invention shown in FIGS. 5 and 6 has the advantage that all except the separate connecting member 15 may be manufactured from a considerably less expensive synthetic material and that the connecting member 15 may be manufactured from a more durable, and therefore better, material. The connecting member 15, thus manufactured from a material of better quality, will be substantially unbreakable and the recording and/or reproducing instrument will be substantially fault-free.

It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.

I claim:

1. A method for making in one piece a chassis for use in sound recording and/or reproducing apparatus and lever means for actuating a piece of equipment carried by the chassis, comprising the steps of:

a. forming said piece by injection-molding with a plastic material, to form a single piece, one portion of which piece constitutes the chassis and another portion of which piece constitutes the lever means and yet other portions of which piece connect said lever means portion to said chassis portion; and

b. connecting said chassis and said lever means portions with a separate connecting means;

c. severing a predetermined number of said other connecting portions thereby to allow said lever means portion to be pivotable with respect to said chassis portion.

2. A method for making in one piece an article of 5 manufacture having first and second parts one of which parts is pivotable with respect to the other, comprising steps of;

a. forming said piece by injection-molding with a plastic material to form a single piece, one portion of which piece constitutes said first part, another portion of which piece constitutes said second part, and yet other portions of which piece connect said first and second parts to each other; b. connecting the first and second parts to each other with a separate connecting member; and c. severing a predetermined number of the other connecting portions to allow one of the two parts to be pivotal with respect to the other of the two parts. 3. A method as set out in claim 2 wherein all of the other connecting portions are severed during the severing step.

4. A method as set out in claim 2 wherein the to predetermined number of other connecting portions severed is one less than the total number of other connecting portions, and the remaining connecting portion is disposed in the direct vicinity of the separate connecting member.

s a: a:

UNITED STATES PATENT OFFICE QERTIFKCATE OF CORECTION 7 Patent No ,489 Dated August 15th, 1972 'Inventor(s) Klaus Westphal It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading of the patent, lines 5 and "Patentyerwerlungsesellschaft" to 6, change -Patentverwertungsgesellschaft.

Signed and sealed this 9th day of January 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR.

ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents FORM PO-105O (10-69) USCOMM-DC 60376-P69 Q US, GOVERNMENT PRiNTlNG OFFICE 1 I969 O-356334 

1. A method for making in one piece a chassis for use in sound recording and/or reproducing apparatus and lever means for actuating a piece of equipment carried by the chassis, comprising the steps of: a. forming said piece by injection-molding with a plastic material, to form a single piece, one portion of which piece constitutes the chassis and another portion of which piece constitutes the lever means and yet other portions of which piece connect said lever means portion to said chassis portion; and b. connecting said chassis and said lever means portions with a separate connecting means; c. severing a predetermined number of said other connecting portions thereby to allow said lever means portion to be pivotable with respect to said chassis portion.
 2. A method for making in one piece an article of manufacture having first and second parts one of which parts is pivotable with respect to the other, comprising steps of; a. forming said piece by injection-molding with a plastic material to form a single piece, one portion of which piece constitutes said first part, another portion of which piece constitutes said second part, and yet other portions of which piece connect said first and second parts to each other; b. connecting the first and second parts to each other with a separate connecting member; and c. severing a predetermined number of the other connecting portions to allow one of the two parts to be pivotal with respect to the other of the two parts.
 3. A method as set out in claim 2 wherein all of the other connecting portions are severed during the severing step.
 4. A method as set out in claim 2 wherein the predetermined number of other connecting portions severed is one less than the total number of other connecting portions, and the remaining connecting portion is disposed in the direct vicinity of the separate connecting member. 